Never before have so many people been connected together in an instantly responsive network through which memes can spread faster than natural viruses. But the notion that taking the whole world online would create a utopia of netizens, all equal in cyberspace, was always a fantasy—as much a delusion as Luther’s vision of a “priesthood of all believers.” The reality is that the global network has become a transmission mechanism for all kinds of manias and panics, just as the combinati...

...the 9/11 attacks were carried out by one network on another network: al Qaeda against the U.S. financial and political system. Yet it was not the immediate damage of the terrorist attacks that inflicted the real cost on the United States so much as the unintended consequences of the national security state’s response. Writing in the Los Angeles Times in August 2002, before it was even clear that Iraq was to be invaded, the political scientist John Arquilla presciently pointed out the fla...

Like the Reformation, the scientific revolution and the Enlightenment were network-driven phenomena, yet they spread faster and farther. This reflected the importance of acquaintances in correspondence networks such as Voltaire’s and Benjamin Franklin’s, communities that might otherwise have remained subdivided into national clusters. It also reflected the way that new social organizations—notably, Freemasonry—increased the connectedness of like-minded men, despite established divisio...

Luther thought the result of his movement to reform the Roman Catholic Church would be what came to be called “the priesthood of all believers,” the sixteenth-century equivalent of Zuckerberg’s “global community.” In practice, the Protestant Reformation produced more than a century of bloody religious conflict. This was because new doctrines such as Luther’s, and later John Calvin’s, did not spread evenly through European populations. Although Protestantism swiftly acquired the ...